Two-storey extensions in High Wycombe
From over-garage bedrooms to full wraparounds, we cover every kind of two-storey extension in High Wycombe.
High Wycombe at a glance
- Postcode districts
- HP11, HP12, HP13, HP14 and HP15
- Area
- Buckinghamshire, England
- Price region
- South East England
- Nearest towns
- Marlow (4.3 miles), Beaconsfield (4.5 miles), Amersham (6.3 miles), Amersham on the Hill (6.9 miles)
- Distance to Milton Keynes
- about 28.5 miles
- Approvals
- Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission.
We cover postcode districts HP11, HP12, HP13, HP14 and HP15 in and around High Wycombe, along with neighbouring Marlow, Beaconsfield and Amersham.
Extensions available in High Wycombe
Two-storey rear extensions
Design, approvals and build for High Wycombe homes. Guide from £61,500.
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Two-storey side extensions
High Wycombe guide price from £94,500, Standard spec.
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Two-storey wraparound extensions
From £132,500 in High Wycombe. Free visit to firm it up.
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Part single, part two-storey extensions
For homes in High Wycombe: typical guide from £79,000.
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Extensions over a garage
High Wycombe guide price from £34,500, Standard spec.
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First-floor extensions
Guide from £27,500 in High Wycombe, including VAT.
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Two-storey extensions for semi-detached houses
Design, approvals and build for High Wycombe homes. Guide from £61,500.
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Two-storey extensions for detached houses
Design, approvals and build for High Wycombe homes. Guide from £94,500.
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Kitchen extensions with bedrooms above
High Wycombe guide price from £61,500 (before kitchen units), Standard spec.
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Extra bedroom and en-suite extensions
Design, approvals and build for High Wycombe homes. Guide from £61,500 (plus en-suite).
Learn moreWhich type suits your house?
Rear and side extensions suit most semi-detached and detached houses with room around them. Terraced and town-centre homes can take a two-storey extension too, with more care over neighbours, light and access.
Also available in Buckinghamshire
- Two-storey front extensions
- Two-storey extensions for end-of-terrace houses
- Two-storey annexe extensions
- Garage conversions with a room above
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Rules for High Wycombe
High Wycombe is in England. Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
The full England rules explained
Questions about extensions in High Wycombe
Do you cover High Wycombe?
Yes. We cover High Wycombe (HP11, HP12, HP13, HP14 and HP15) and the surrounding area, including Marlow and Beaconsfield. The first site visit is free.
What does a two-storey extension cost in High Wycombe?
Using our South East England guide, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) is about £61,500–£83,000 including VAT. An extension over a garage is about £34,500–£50,500.
Which other places near High Wycombe do you cover?
Everywhere around it, including Marlow (4.3 miles), Beaconsfield (4.5 miles) and Amersham (6.3 miles), and the rest of Buckinghamshire.